TNCS or TNS earthing arrangement?

[Dunisan]

Please can someone explain if this is a TNCS or a TNS earthing arrangement because it looks like both to me. Old undersized main bonding conductor goes into the neutral block first then to an earth block that's connected to the incoming cables sheath. My rather unhelpful supervisor told me to "figure it out for myself" today, I think someone was having a bad day...

If the consumer unit is getting swapped out would you run the replacement 16mm main bond to the Neutral block and 10mm supplementary bonding to the earth block on the side of the incomer shown below, gas and water so you would have 3 supplementary bonding cables?

Thanks

 

[rewireIT]

I think you can ring the DNO to confirm.

 

[westward10]

Was TN-S is now TN-C-S.

 

[mainline]

Please can someone explain if this is a TNCS or a TNS earthing arrangement because it looks like both to me. Old undersized main bonding conductor goes into the neutral block first then to an earth block that's connected to the incoming cables sheath. My rather unhelpful supervisor told me to "figure it out for myself" today, I think someone was having a bad day...

If the consumer unit is getting swapped out would you run the replacement 16mm main bond to the Neutral block and 10mm supplementary bonding to the earth block on the side of the incomer shown below, gas and water so you would have 3 supplementary bonding cables?

Thanks

View attachment 109121

Phone the Dno and ask them to upgrade.

 

[westward10]

It was TN-S, it is possible earth continuity broke down and it was changed and the existing earth braid was connected into the earth terminal to earth the cable sheath, it doesn't need upgrading it isn't uncommon.

 

[loz2754]

Indeed it is clearly marked as a PME earthing system, which means it is TNCS.